Meissner’s plexus (after the German scientist G. Meissner, 1829–1905), in vertebrates and man, the aggregation of bundles of neural fibers and clusters of nerve cells in the submucosa of the organs of the digestive tract.

The neural ganglia of the submucosal plexus are made up of poorly differentiated cells, whose number decreases with age, and two types of polydendritic neurons. The poorly differentiated cells divide and replace dead neurons. The first type of polydendritic neurons are motor cells that receive stimuli from the central nervous system through the vagus nerve and its parasympathetic sacral branches or from neurons of the second type. The second type are sensory cells outside the central nervous system that transmit stimuli to the smooth muscles or the glands of the organs that regulate the motor and secretory functions of the digestive tract.